Unit 3

Human Population

• Population: all the organisms that both belong to the same species and live in the same geographical area

• Demographics: statistics about characteristics of a human population

• Examples: gender, race, age, income, disabilities, educational attainment, home ownership, employment status, etc.

Quick Facts

• Since the early 1800s, the human population on Earth has been growing exponentially.

• Current world population estimate is: 6,872,195,424 people as of October 1, 2010

• The Earth’s human population is increasing by:

• 2.5 people / sec., 150 people/min, 9,000/hr., 214,000 / day, 78 million/year.

• U.S. = 4.6% of the world’s population, we consume 40% of the resources. (In other words, we are greedy gremlins.)

• Each dot represents 1 million people

Why has the human population increased exponentially over the past 100 years?

• There has been a decrease in the death rate, especially in developing countries

• Why the decrease? Improvement in sanitation and health care.

•The overall rate of population increase depends on the number of births and deaths, but also on the length of generations -- the age at which women have their first baby.

• Total fertility rate (TFR) - estimate of the average number of children a woman will have during childbearing years

•This map shows the average number of children born to a woman during her lifetime.

•The darker the color, the greater the number of children.

•Childbearing years are usually considered to be the ages of 15-49.

What factors affect the fertility rate?• Level of education and affluence• Importance of children in the workforce• Degree of urbanization• Opportunities outside of home for women• Infant mortality rate• Availability of pensions• Religious beliefs or cultural norms• Cost of raising and educating kids• Average age of marriage• Availability of abortions• Availability of birth control

• Mortality rate: a measure of the number of deaths in a population

• Mortality rate is typically expressed in units of deaths per 1000 individuals per year

Death Rates per 1000 over Time

What factors affect the death rate?• Increased food supply and

distribution• Improved nutrition• Improvements in health care

–immunizations–antibiotics

• Improvements in sanitation• Safe water supplies

Developed or Developing?

• Developed Country: a nation that has a high level of material well-being according to some criteria, usually average income, industrialization, life expectancy, health care, and/or education.

• Developing Country: a nation with a low level of material well-being (not to be confused with third world countries). the levels of development may vary widely within this category

• “Newly Industrialized Countries” is used for countries in between these two categories.

• Kofi Annan, former Secretary General of the United Nations, defined a developed country as follows: "A developed country is one that allows all its citizens to enjoy a free and healthy life in a safe environment."

MAIN IDEA:

Developed countries have

similar birth and death rates.

Developing countries have

higher birth rates than death

rates.

Life Expectancy• Life Expectancy: the number of years that one

is expected to live as determined by statistics.

• Women have higher life expectancies than men in countries with modern obstetric care (health care during pregnancy & childbirth)